The invention in general is directed to a transparent article having a visually observable contrast between coatings deposited over a substrate or between coatings deposited over a substrate and uncoated surfaces of the substrate, to provide a patterned surface. One of the coatings exhibits a reflected color and a differing transmitted color, at least one of which differs from the reflected color or transmitted color of the other coating(s) or the uncoated surface of the substrate. The invention is also directed to methods of making the articles.
Coated articles, particularly glass substrates having one or more coatings deposited thereon are presently available. The coatings can be deposited by a variety of processes including magnetron sputter vacuum deposition (MSVD), chemical vapor deposition (CVD), spray pyrolysis process and the sol-gel method, among others.
It is known that certain coatings or combinations of coatings alter the interaction between electromagnetic energy, more particularly visible light energy and the substrate, e.g. alter reflected, transmitted or absorbed visible light some of which is by interference effects as noted in U.S. Pat. No. 4,902,581 (Criss). xe2x80x9cInterference effectxe2x80x9d involves the visually observable constructive or destructive combination of visible light waves or rays as they are transmitted through or reflected from the coatings and/or substrate. Absorption occurs in certain materials in the visible region of the light spectrum where the electromagnetic energy does not pass through the material.
The interference effect is usually visually observed as a decrease in reflected light (e.g. anti-reflective coatings), as a transmitted color and/or as a reflected color which differs from that which would have been observed in the absence of the interference effect.
Forming low reflectance, highly saturated colored coatings in monolithic glazing using coatings that exhibit color by interference effects are described in U.S. Pat. No. 5,112,693 to Gillery.
In view of the presently used technology, it would be advantageous to provide articles, as for example, for decorative or aesthetic purposes, among others, by utilizing coatings over a substrate to exhibit differential interference effects.
The present invention is directed to an article having a visually observable pattern. The pattern is provided by the contrast between at least one first and at least one other portion of a substrate, e.g. a glass, metal, or ceramic substrate. The at least one first portion has a thin film coating, e.g. which is generally transparent, exhibiting a first visually observable color or contrast when viewed under reflected light (hereinafter xe2x80x9creflected colorxe2x80x9d) and a second visually observable color or contrast which can be that when viewed under transmitted light (hereinafter transmitted color). The at least one other portion to provide the contrast may be uncoated, coated with one or more non-colored (i.e. neutral) thin film coatings or coating layers, and/or coated with one or more thin film coatings having a reflected color and/or transmitted color, where at least one of the reflected color and/or transmitted color of the at least one other portion differs from the reflected color and/or the transmitted color of the at least one first portion. The transmitted color can be that from transmitted light through a substrate. The at least one coating for the thin film layer or otherwise referred to as the thin film coating can be chosen from metals, metal oxides metal nitrides, semi-conductor materials and mixtures and combination thereof. All of these materials should have the capability of being deposited by magnetron sputtering vacuum deposition (xe2x80x9cMSVDxe2x80x9d), chemical vapor deposition (xe2x80x9cCVDxe2x80x9d), pyrolytic coating techniques or sol-gel techniques or the like known to those skilled in the art.
The present invention is also directed to a method for providing an article having a visually patterned appearance by the following steps. First, at least one surface portion of a substrate, e.g. a glass, metal, and/or ceramic substrate, is masked. At least one coating is deposited, e.g. by MSVD, CVD, spray pyrolysis, or sol gel techniques, as a thin film over the masked and unmasked portions of one or more surfaces of the substrate. The mask along with any coating deposited on the mask is removed to expose the surface portion to provide a patterned appearance as a contrast between the deposited thin film coating and the at least one surface portion of the substrate.
The present invention is also directed to a method for providing an article having a visually patterned appearance which involve the following steps. At least one coating is provided which can exhibit a first reflected color and/or a first transmitted color at a first thin film coating thickness and either a second reflected color, a second transmitted color or both, at one or more other thickness over one or more surface portions of a substrate. The thickness of one or more thin film layers of one or more types of coatings is varied one or more times in the thin film thickness dimensions, of the coating over one or more surface portions of the substrate in a pattern form to provide a patterned appearance when the article is observed under reflected light, transmitted light, or both. As with the use of different types of thin film coatings, the patterned appearance is formed by the contrasting reflected and/or transmitted colors or contrasts.
The original surface portion of the substrate in any embodiment of the article and method of the present invention may have a coated, uncoated, roughened or textured surface. The thickness may be varied during the coating deposition step as by differentially depositing the coating over selected portions of the surface of the substrate. Alternatively, the thickness may be varied after the coating has been deposited by removing a portion of the coating in a pattern form. The coating can be applied as a thin film to the substrate and subsequently or simultaneously heated in an oxidizing or nitriding atmosphere to give the patterened appearance with one or more oxide or nitride materials. A portion of the coating may be removed by depositing the coating over a mask during the deposition step, and subsequently removing the mask and the coating deposited thereon. Alternatively, a portion of the coating may be removed or the original substrate roughened or texturized by etching or milling. Combinations of the foregoing are also contemplated as within the scope of the present invention. Also the article with the pattered appearance can be produced into a laminate with one or more non-patterned substrates or with one or more other patterned articles.